A course of action is an action or a series of actions that you can do in a particular situation.
做法 Aircraft can avoid each other by altering course to left or right. 飞行器可以通过向左或向右改变航线来避免相撞。
If a ship or aircraft is on course, it is travelling along the correct route. If it is off course, it is no longer travelling along the correct route.
在正确路线上/偏离正确路线